i’m New to blender and I’ve had a dabble with rendering bokeh. I have made this image with transparent orange blobs in blender render using refocus node. 
In the image the orange blob is in the foreground and the background is nicely blurred from the defocus node. Unfortunately where the background passes through the orange blobs the defocus is not rendered. The orange blob has transparency frezel applied. Anybody know how to get it to render bokeh through objects? Thanks!!
This is the downside of post processed depth of field. You see, the depth map is a 2D image. To create it, rays get shot into the scene and depending on how far away from the camera they hit an object, the corresponding pixel gets a grey value. (white if in front of the camera, black if far away)
Because of that there is no information in the depth map how far away the objects in the background are. The same problem occurs if you render through a glass window. The depth map would be totally flat in that case.
So I would recommend rendering the scene with camera dof turned on, rather than adding it in post. Also, adding dof in post is a cheat and will never look as well.
